Unless I'm mistaken, there's no support for serializing fusion sequences
using Boost.Serialization.
I had an hour over at work today and hacked together something.. It can be
accessed from here:

git_at_[hidden]:cholmquist/fusion-serialize.git

I only tested it on MSVC-2005, didn't write any docs, but if there's
interest I could do the additional work..
Unless there's something fundamentally flawed with my implementation.. I do
wonder why this hasn't been added previously (?).